Engraving is a process [which] the surface of metal is [first covered]
with [an acid] and then inscribed with some sharp [instrument].

which first covered an acid instrument

142.

For
many [years ago], [much of] what was possible to know was derived [from] inspiration
or divination and did not involve the rational process of reasoning in [wide use]
today.

years
ago much
of from
wide use

143.

Ayn
Rand, ______ novels deal with the nature of capitalism in a democracy, is often
taught in introductory courses in economics.

of
many whose whose many of whose of many many
of whose

144.

The
formation of a rainbow [occurs] a process in which light is diffused at [varying]
rates by the surrounding atmosphere, [resulting in] the reflection of different
[wavelengths] of light.

occurs
varying
resulting in
wavelengths

145.

[Though]
difficult, it [possible] for an adult learner of a new language [to master] the
subtleties of the grammar and syntax of [the new] language.

Though
possible to
master the
new

146.

When
a bird molts, ______ loses its feathers, it is actually preparing itself for the
regeneration of the lost feathers.

so its as
if as when it so
that

147.

The
scientific method is a system [which] a problem or challenge [is] identified and
possible solutions are created and tested, [with] the final results evaluated
to determine the best approach to the [resulting] theory.

which
is with
resulting

148.

The
Smithsonian Institution in Washington D.C. is [home to] the largest [collecting]
of Native American artifacts in the United States, most [of which] remain [uncatalogued]
and hidden from public view.

home
to collecting
of which
uncatalogued

149.

Many
modern critics of American literature have called Mark Twain, born Samuel Clemens,
______ .